Rotatable stop for metal-working machines



March 29, 1949. B. P. TOTH 2,

ROTATABLE STOP FOR METAL WORKING MACHINES Filed A ril'zo', 194s IN V EN TOR.

zv gmww Patented Mar. 29, 1949 ROTATABLE STOP FOR METAL-WORKING MACHINES Barnabas P. Toth, Bridgeport, Conn, assignor to Barnaby Manufacturing and Tool Company,

Bridgeport, Conn a partnership Application April 20, 1945, Serial No. 589,318

1 Claim. 1

This invention relates to a rotatable stop for metal working machines, such, for example, as

automatic lathes, automatic screw machines, and the like, and more particularly to a stop against which the bar of stock is fed in the feeding operation to limit the feeding movement of the stock and determine the amount of feed, and has for an object to provide an improved and simplified construction of such a stop in which the stop member is rotatable to prevent wear, from the end of the stock bar and to maintain a more accurate position, and in which the rotatable stop member is eifectively locked in position, but may be readily removed if desired for grinding, renewal or repair.

With the foregoing and other objects in view, I have devised the construction illustratedin the accompanying drawing forming a part ofthis specification. It is, however, to be understood the device is not limited tothe specific details'of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In this drawing:

Fig. 1 is a somewhat diagrammatical side elevation showing the stop in operation;

Fig. 2 is a partial side elevation and partial longitudinal section of the improved stop, and

Fig. 3 is a transverse section substantially on line 3-3 of Fig. 2.

In Fig. 1 the stop is shown as mounted in the rotatable turret or other tool support 5 of an automatic lathe or other metal working machine, against which a bar of stock 6 may be fed forwardly by suitable feed mechanism, not shown, to determine the amount of stock to be fed into working position, and then gripped by any suitable chuck to be held and rotated during the cutting or other working operations on the bar by suitable tools, not shown. My improved stop comprises a shank 8 adapted to be inserted in a socket or other holding means in the support or holder 5 and clamped therein by any suitable means such as a clamp screw 9. This shank is provided with a socket Ill extending longitudinally inward from its outer end, and the shank may or may not be somewhat enlarged at its outer end portion, as shown at H, Mounted within the socket is a rotatable stop member l2 including a stem l3 and preferably a somewhat enlarged head l4, although not necessarily so, the stem being mounted in the socket It! with suitable bearings to permit rotation of the stop member l2 and also locate it in proper position so that its outer end acts as a limit stop for feeding movements of the stock bar 6.

Preferably there is a bearing bushing I5 mounted in the outer portion of the socket l0, although the socket l0 may itself form the bearing for the stem l3. This bearing bushing i5 is preferably of bronze or. similar bearing material, and has an enlarged head'lli resting against the outer end of the shank 8! 'At' its inner end the shank i3 is provided with'a socket H to receive a steel ball 18 formlnga thrust bearing for the'rotatable stop member I2. This may rest directly against the inner end of the socket H], but preferably a hardened steel block or plate i9 is mounted at the inner end of. the socket against which the ball thrust bearing, l8 rests. It is preferred that this bearing member {El and the ball l8. be so located and the stem"'l'3 be of such length that the head l l'of the rotatable member is spaced a short" distance" from'the outer end of the bushing !5, as shown in Fig. 2, for clearance, and to permit free rotation of the member l2.

' Improved means is provided for looking or retaining the rotary stop member 12 in the shank. For this'a transverse or radially extending opening 20 is drilled through the side Wall of the shank 8 and bushing l5 to receive a retaining member 2!, which is preferably a steel ball, although it could be of other form, and the stem I3 is provided with a coacting peripheral shoulder, preferably in the form of a groove 22 in alignment with the opening 20 to receive and substantially fit the inner portion of the retaining member or ball 2|, so that the inner portion of the retaining member projects into the groove 22 to retain the rotatable member !2 in the socket. It also acts to retain the bushing l5 in the socket.

The ball 2| is retained in position in the side opening 20 by means of a sleeve 23 embracing the shank 8 and slidable longitudinally thereon so that it may be shifted to a position to cover the outer end of the opening 20. This sleeve has a rather tight sliding fit on the shank 8 so 40 that it normally retains its position but may be shifted longitudinally on the shank to and from its position over the opening 28. In assembling. after the bushing 15 and rotatable member l2 are mounted in position, the retaining member or ball 2! is inserted in position in the opening 20, and then the sleeve 23 is slid into position over this opening to retain the ball in position.

There is a coacting camming action between the wall of groove 22 and the retaining member 2|, so that a pull on the rotatable member l2 tending to pull it outwardly will force the retaining member or ball 2! outwardly and press it against the sleeve 23 and thus clamp this sleeve in position and preventing its moving out of position. It is also preferred that the ball 2! and the bushing 26 be so proportioned that the line 24 indicating the outer diameter of the bushing be inward somewhat from the center 25 of the ball, so that any tendency of the bushing I5 to move outwardly would also have a camming action on the ball 2| and tend to force it outwardly against the sleeve 23 to clamp it in position. The cavities l1 and I may be packed with grease for proper lubrication.

It will be apparent from the above that this provides a very simple mounting for the rotatable stop member I2, and as a greater part of the thrust on this member is longitudinal this will be taken by the antifriction thrust bearing l8. However, the rotatable member is efiectively locked in position within the shank by the 00- action of the retaining member and the groove 22 without interfering with free rotation of the stop member I2, and any longitudinal pull or force on the rotatable member automatically clamps the retaining sleeve 23 in position, which in turn holds the retaining member 2| in proper position. However, if desired, the looking or retaining member 2| and the rotatable member I2 may be removed from the shank by merely first sliding the sleeve 23, longitudinally on the shank from its position over the opening 20 to release the looking or retaining member 2 I. This makes a very simple and effective construction for mounting a rotary or live stop, and one which will remain accurate during unlimited operation.

Having thus set forth the nature of my invention, what I claim is:

A stop of the character described comprising a shank adapted to be gripped in a support and provided with a socket extending longitudinally inward from one end, a rotatable stop member provided with a stem projecting into th socket, said stem being provided with a socket in its inner end, a ball mounted in said latter socket forming a thrust bearing for the stem, a bearing bushing embracing the stem and mounted in the outer portion of the socket in the shank, said shank and bushing being provided with aligned openings through their side walls, a ball in said openings to lock the bushing in the shank, a sleeve slidable on the shank to a position over the opening to retain the ball therein and having a sufiiciently tight fit on the shank to normally retain it in this position, and said stem being provided with a peripheral groove in which the second ball extends to retain the rotatable mem-- her in the shank and adapted by a camming action from a longitudinal pull on the rotatable member to force the ball outwardly against the sleeve to clamp it in position over the opening during said pull, the second ball being of a diameter substantially equal to the distance from the bottom of the groove to the inner surface of the sleeve.

BARNABAS P. TOTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Gordon May 13, 1930 

